TheTonga plate is a small southwest Pacifictectonic plate or microplate. It is centered at approximately 19° S. latitude and 173° E. longitude. The plate is an elongated plate oriented NNE–SSW and is a northward continuation of the Kermadec linear zone north of New Zealand. The plate is bounded on the east and north by thePacific plate, on the northwest by theNiuafo’ou microplate, on the west and south by theIndo-Australian plate. The Tonga plate is subducting the Pacific plate along theTonga Trench. This subduction turns into atransform fault boundary north of Tonga. An active rift or spreading center separates the Tonga plate from the Australian plate and the Niuafo’ou microplate to the west. The Tonga plate is seismically very active and is rotating clockwise.
These were the plates that moved when the2009 tsunami hit Samoa.
